Fabrication and Mechanical Properties of Carbon Fiber Reinforced Silicon Carbide Composites

Silicon carbide composites reinforced with unidirectionally oriented carbon fibers have been fabricated by slurry impregnation followed by hot pressing. Identification of crystalline phases, observation of the metallographic structure, and measurement of flexural strength and fracture toughness at room and high temperatures in vacuum were carried out. The flexural strength and fracture toughness were 420MPa and 13MPa√m at room temperature and were about 600MPa and 20MPa√m at 1400° to 1600°C. The improvement of the mechanical properties at high temperatures was explained by the suppression of crack propagation and by the increment of fiber pull-out due to softening of boundaries.